PROJECT SUMMARY Funds are being requested to purchase a state-of-the-art BD Biosciences (BD) FACSAria Fusion fluorescence activated cell sorter for the Oregon Health & Science (OHSU) Knight Flow Cytometry Shared Resource. This shared resource is a university-wide core facility (Core) that is available to all OHSU investigators. The proposed 5-laser 18-color instrument will replace a highly used, aging, maximally upgraded BD FACSAria-I sorter that is no longer performing to the standards required by our investigators. For example, sorted cell recovery has declined dramatically over the last year, despite frequent servicing by BD engineers and daily maintenance and QA/QC assessments. Thus, the requested instrument will allow the Core to meet current and future researcher needs. We are also requesting an upgrade to the instrument's biohazard containment capabilities, to ensure safe operation by Core staff and investigators; and the addition of a UV laser, to enable use for additional applications. The Core was established in 1996 and has been directed by Philip R Streeter, PhD, for the past 14 years. Dr. Streeter works closely with the Core's 5 highly skilled flow cytometry operators to ensure delivery of the public health related goals of the flow cytometric research of our many investigators. The Core serves a user base of approximately 120 investigator laboratories, and provides advanced instrumentation, expertise, and infrastructure to fully support research needs for analytical flow cytometry and cell sorting. Services offered include: consultations, contributions to grant applications, education, training, data analyses, soluble analyte quantification, analytical flow cytometry, and cell sorting. Hands-on training provides investigators with the requisite tools and the background for comprehensive high-quality experimental design and data analyses. Further, Core operators work closely with investigators to promote excellence in acquisition and analyses of flow cytometric data. Cell sorting enables purification of live cell populations from complex cell mixtures. Cells can be sorted into bulk populations or as single cells, and they can be deposited into wells, into tubes, or onto slides. Sorted cells are used for in vitro cell culture; in vivo biological studies; or molecular, genetic, or proteomic analyses. Sorting enhances the power of those technologies by yielding defined samples. Sorting enables investigators to qualitatively and quantitatively assess cells tagged with fluorophore-labeled reagents or fluorescent proteins, and provides investigators with the ability to isolate specified cell populations. The requested instrument is also able to sort cell type specific extracellular vesicles, a technology being optimized for multiple applications at OHSU. Acquisition of the requested instrument will support the Core's mission of delivering high quality flow cytometric data to our many investigators, and it will facilitate delivery of the public health related goals of their research.